It is generally accepted that flood risk has been increasing in Europe in the last decades. Accordingly it becomes a priority to better understand its drivers and mechanisms. Flood risk is evaluated on the basis of three factors: hazard, exposure and vulnerability. If one of these factors increases, then so does risk. Urban expansion and associated land use dynamics are recognised as one of the main causes of increased flood risk in Europe. Land use change models used for ex-ante assessment of spatial trends provide planners with powerful tools for territorial decision making. However, until recently this type of models has been largely neglected in strategic planning for flood risk mitigation. Thus, ex-ante assessment of flood risk is an innovative application of land use change models. The aim of this paper is to propose a flood risk mitigation approach using exposure scenarios. To that effect, a cellular automata land use change model is used for exploring different development scenarios. The proposed methodology enables to weigh off the effects of urban and regional planning instruments and policies against the option of no intervention. The methodology is applied in the Pordenone province in northern Italy. In the past 50 years Pordenone has suffered several heavy floods, the disastrous consequences of which demonstrated the vulnerability of the area. Historical land use maps and scenarios simulated with the land use model are used for flood risk assessment in an integrated spatio-temporal context. Results of this study confirm that the main driving force of increased flood risk is found in new urban developments in flood-prone areas.